Nitrogen determination and apparatus therefor

ABSTRACT

A method and apparatus for quantitatively determining the nitrogen content of organic materials, especially those organic materials having boiling points in excess of about 450* F. The method involves hydrocracking the organic material, hydrogenating the nitrogen to ammonia, and measuring the quantity of ammonia present, which may then be related to the original nitrogen composition.

United States Patent [72] Inventor Itsumi Jack Oita Chicago, Ill. [21]Appl. No. 717,889 [22] Filed Apr. 1, 1968 [45] Patented Oct. 26, 1971[73] Assignee Standard Oil Company Chicago, Ill.

[54] NITROGEN DETERMINATION AND APPARATUS THEREFOR 20 Claims, 2 DrawingFigs.

[52] U.S. Cl 204/1 T, 23/230 l-lC, 23/230 M, 23/232 E, 23/253 R, 23/254E, 204/195 [51] Int. Cl ..G0ln 27/42 [50] Field of Search 204/1.l, 195;23/230, 232, 253, 254 E; 208/97, 111

[56] References Cited UNITED STATES PATENTS 3,438,887 4/1969 Morris etal. 208/111 X HUMIDIFIER I l 7 3,468,788 9/1969 Wilkinson 208/111 X3,503,871 3/1970 Gladrow et al. 208/111 3,461,042 8/1969 Martin et a1.204/1 OTHER REFERENCES Ronald L. Martin, Analytical Chemistry, Vol. 38,No. 9, pp. 1209- 12l3,(l966).

Dohrmann Tech. Bulletin 508 Dohrmann Tech. Bulletin 522 Journal ofGasChromatography, p. 9A, July 1966.

Primary Examiner-G. L, Kaplan Attorneys-Arthur G. Gilkes and William T.McClain ABSTRACT: A method and apparatus for quantitatively determiningthe nitrogen content of organic materials, especially those organicmaterials having boiling points in excess of about 450 F. The methodinvolves hydrocracking the organic material, hydrogenating the nitrogento ammonia, and measuring the quantity of ammonia present, which maythen be related to the original nitrogen composition.

TITRATION CELL COULOMETER RECORD R \HYDROGENATION E *HYDROCRACKING ZONEVAPORIZING PATENTEDUET 2 6 ISTI SHEET 2 BF 2 V HYDROGENATION ZONE/HYDROCRACKING ZONE g7 Hydrogen VAPORIZING ZONE INVENTOR. lfsumi JackOifa A TTOR/VEY NITROGEN DETERMINATION AND APPARATUS THEREFOR BACKGROUNDOF THE INVENTION My invention relates to a method and apparatus forautomatic quantitative analysis. More specifically, it relates to animproved method and apparatus for analyzing the nitrogen composition ofnitrogen-containing materials. In particular, my invention relates to amethod and apparatus for hydrocracking nitrogen-containing organicmaterials, hydrogenating the nitrogen contained therein to ammonia, andmeasuring the ammonia present in the material from which the originalnitrogen composition of the material can be determined. Coulometrictitration means are particularly advantageous and convenient for therequired ammonia analysis.

Rapid and accurate organic nitrogen determinations are of greatimportance in many processes, particularly in the petroleum industry. Incertain refinery processes, especially those using platinum catalysts,the presence of nitrogen compounds have a deleterious effect on theprocess due to nitrogen poisoning of the catalyst. On the other hand, inother processes, the presence of certain nitrogen compounds in theprocess streams is necessary. An example of this is when nitrogencompound additives are blended into lubricating oils. The level ofnitrogen present in process streams can range from less than a few partsper million to well over 5 percent. Furthermore, the boiling point ofnitrogen-containing materials in process streams can range from about150 F., as in naphtha, to over l,000 F. for certain oil additives.Therefore, it is difficult to have a single method and apparatus whichcan determine the nitrogen composition of most of the process streamsfound in a refinery. As a result of this, improved methods and means fornitrogen analysis of samples having widely varying properties are ofgreat importance to those in the petroleum industry.

Essentially, most methods for the determination of nitrogen use one ofthree basic approaches: Kjeldahl, Dumas or ter Meulen. Modifications andimprovements of these three basic approaches are many, but none haveachieved the desired goals of high sensitivity and short analysis time,and can also be used in analyzing high-boiling nitrogen-containingsamples. Usually, the nitrogen content of a sample can be determined bythe Kjeldahl method, which employs sulfuric acid digestion and steamdistillation of ammonia. This method, although being quite sensitive,requires a relatively long digestion time so that the total timerequired in an analysis can be from 2 to 6 hours. For many applicationsthis lengthy analysis time is unsatisfactory. The Dumas method,involving the oxidation of nitrogen compounds over copper oxide and thesubsequent reduction of the nitrogen present to elemental nitrogen,requires less time for analysis but is less sensitive. The ter Meulenmethod involves the catalytic production of ammonia fromnitrogen-containing compounds and the subsequent measurement of theammonia formed. This method offers the advantages of both highsensitivity and relatively short analysis times. The drawback to the terMeulen method, up to this time, is that it has not been adaptable to theanalysis of higher boiling nitrogen-containing materials.

The ter Meulen method converts nitrogen to ammonia by hydrogenation overa nickel-on-magnesia catalyst. lnvestigations show that at temperaturesof from about 600 to about 750 F., the alkaline nickel-on-magnesiacatalyst traps and holds acidic gases such as H 8 and HCl. Then, attemperatures above 750 F these acidic gases are slowly released and passwith the ammonia to the device used in measuring the ammonia present.The gases may then interfere with the required ammonia analysis. Sincetemperatures in excess of l,000 F. are often required for vaporizationof certain nitrogen-containing organic materials such as heavy cycleoils, decanted oils, lubricating oils and lubricating oil additives, thenickelon-magnesia catalyst would necessarily be at a temperature atwhich the acidic acids are released and thus such high boiling samplescannot be analyzed using the basic ter Meulen method.

Prior art nitrogen analyzers have often had difficulty in analyzingviscous, nitrogen-containing samples because of problems encountered inintroducing the sample into the analyzer. Conventional methods ofintroducing nitrogen-containing samples into nitrogen analyzers are bydrawing the sample into a long needle syringe, introducing the needle ofthe syringe into a permeable septum system built into the analyzer, andinjecting the sample through the needle into the analyzer. Viscous,nitrogen-containing samples will not flow easily through the relativelysmall bore syringe needle and, therefore, such a method often becomesimpractical My invention includes a method and apparatus for eliminatingthis problem.

The method and apparatus of my invention are improvements over theinventions claimed and disclosed in U.S. Pat. No. 3,461,042. This patentdiscloses a method for nitrogen determination by the catalyticconversion of nitrogen to ammonia and the coulometric titration of theammonia so produced. The invention of this patent requires the use ofthe nickel-on-magnesia ter Meulen catalyst and therefore is limited tothe analysis of lower-boiling nitrogen-containing materials. Myinvention, however, extends the use of the apparatus and method of thatpatent application to the analysis of higher-boiling samples.

SUMMARY OF THE INVENTION I have found that the determination of nitrogenin nitrogencontaining materials can be improved by first hydrocrackingthe material, in the presence of hydrogen and a suitable hydrocrackingcatalyst, to lower molecular weight components and then hydrogenatingthe lower molecular weight components to convert the nitrogen present toammonia. The hydrocracked products will have a lower boiling point thanthe original sample and can thus be hydrogenated at lower temperatures.A suitable catalyst for hydrocracking the nitrogen-containing materialcomprises rhodium on either a silica-alumina base, a molecular sievebase or a base comprising mixtures of silica-alumina and zeoliticmolecular sieve material. Additionally, I have found that thedetermination of nitrogen present can be improved by passing thehydrocracked material through a bed of nickel granules immediately afterpassing it through the hydrocracking catalyst. It is understood that theterm nickel granules is intended to include nickel shot, nickelparticles, nickel turnings and other particulate forms of nickel. Forbest results, the hydrocracking catalyst should be at a temperature ofabout l,400 F. and if a bed of nickel granules is also used, this bedcan also be at about 1,400 F. or somewhat lower.

In order to perform the steps of hydrocracking and hydrogenation, it isnecessary to mix the vaporized nitrogencontaining sample with a carriergas. The carrier gas acts to dilute the sample and to sweep it throughthe zones of hydrocracking and Although any nonnitrogen-containing inertgas may be used as the carrier, it is most advantageous to use hydrogengas for this purpose since hydrogen is required in the hydrocracking andhydrogenation steps. Humidifying the hydrogen gas is effective ininhibiting the coking of the hydrocracking catalyst.

The apparatus for determining the nitrogen content of anitrogen-containing material which uses the method of my inventioncomprises a reactor, including zones for vaporizing, hydrocracking andhydrogenating the sample and a means for analyzing the reactor effluentfor nitrogen contained therein. Various means of analyzing the nitrogenare possible but one that has been found most convenient comprises anautomatic coulometric titrator as described in U.S. Pat. No. 3,461,042.Means for introducing hydrogen into the reactor must be provided andpreferably this means should also include provisions for humidifying andheating the hydrogen gas.

In order to solve the problem of introducing viscous nitrogen-containingmaterial into the nitrogen analyzer without permitting the escape ofcarrier gas or the vaporized, nitrogen-containing material, I have foundthat the nitrogen material should be encapsulated in a substance whichmelts at a temperature no higher than the temperature encountered in thevaporizing zone of the nitrogen analyzer. The encapsulatednitrogen-containing material is then introduced into the vaporizingzone. The encapsulated material may be introduced into the analyzerthrough a vapor lock" zone comprising a chamber communicatingalternatively with the nitrogen analyzer vaporizing zone and theexterior of the analyzer. In this manner an operator may insert thesamplecontaining capsule into the chamber, interrupt the communicationbetween the exterior of the analyzer and the chamber, and initiatecommunication between the chamber and the vaporizing zone of thenitrogen analyzer so that the capsule is introduced into the vaporizingzone.

BRIEF DESCRIPTION OF THE DRAWING Hg. 1 is a schematic view of thecomplete nitrogen determination system showing a hydrogen humidifier, areactor, and a titration cell.

FIG 2 is an enlarged view of the reactor, partially in section, showingthe vaporization, hydrocracking and hydrogenation zones, as well as animproved sample inlet means.

DESCRIPTION OF A PREFERRED EMBODIMENT Briefly, the method of myinvention for automatically determining the nitrogen content of anorganic material involves the steps of passing the organic materialthrough a hydrocracking zone to crack the organic material into lowermolecular weight components, converting the nitrogen in the material toammonia by hydrogenation and determining the quantity of ammoniaproduced. In my method, the hydrocracking zone includes a suitablehydrocracking catalyst such as one comprising rhodium on asilica-alumina base, a molecular sieve base or on a base comprising amixture of silica-alumina and zeolitic molecular sieve material. It hasbeen found that a hydrocracking catalyst containing about 0.6 percentrhodium is effective. After hydrocracking the sample, the nitrogen isconverted to ammonia by passing the hydrocracked material through ahydrogenation zone containing a suitable hydrogenation catalyst. Onetype of hydrogenation catalyst which has been found to be suitablecomprises nickel on a magnesia base. Conveniently thenitrogen-containing sample is mixed with a carrier gas such as hydrogenprior to being passed through the hydrocracking and hydrogenation zones.In order to inhibit coking of the hydrocracking catalyst, humidificationof the hydrogen gas carrier has proven satisfactory.

More specifically, my method comprises introducing thenitrogen-containing material into a vaporizing zone, mixing thevaporized material with humidified hydrogen, passing the vaporizedmaterial and humidified hydrogen through a hydrocracking zone at atemperature in the range of between about l,400 F. and about l,440 F.,passing the vaporized hydrocracked product and humidified hydrogenthrough a bed of nickel granules at a temperature in the range ofbetween about 1,400 F. and l,440 F., passing the hydrocracked materialand humidified hydrogen through a hydrogenation zone at a temperature inthe range of between about 680 F. and about 750 F. to convert thenitrogen present to ammonia, and coulometrically titrating the ammoniaproduced in the hydrogenation zone to determine the amount therein. Forviscous samples, the nitrogen-containing material is convenientlyintroduced into the vaporizing zone by encapsulating it in a materialwhich melts at a temperature no higher than that encountered within thevaporizing zone and introducing the encapsulated material into thevaporizing zone through a vapor lock. Less viscous samples ofnitrogencontaining material can be introduced into the vaporizing zoneby means of the syringe and septum technique described above.

The apparatus ofmy invention, for determining the nitrogen content of anorganic material, comprises a reactor including a vaporizing zone, ahydrocracking zone, a hydrogenation zone, and an analyzing means incommunication with said reactor for quantitatively detecting thepresence of ammonia. The reactor provides for the passage of thenitrogen-contain ing sample sequentially through the vaporizing,hydrocracking and hydrogenation zones, and further provides for thepassage of a sample to the analyzing means. The vaporizing zone includesa heating means sufficient to permit the passage of thenitrogen-containing sample into the hydrocracking zone as a vapor.Accordingly, the heating means should be capable of heating the sampleto a temperature of at least about 1,400" F. The hydrocracking zone mustcontain a hydrocracking catalyst, such as the conventionalsilica-alumina base catalyst, or the newer molecular sieve-typehydrocracking catalyst. The incorporation of minor amounts of rhodium oneither the silica-alumina base catalyst or the molecular sieve catalystprovides improved hydrocracking performance. About 0.6 percent rhodiumhas been found to be a suitable amount to incorporate in thehydrocracking catalysts of my invention. Furthermore, I have found thatproviding a bed of nickel granules subsequent to the hydrocracking zoneimproves and enhances the operation of the apparatus.

The hydrogenation zone includes a suitable hydrogenation catalyst suchas is described in 24 Analytical Chemistry 1755-1756. Modifications ofthat particular catalyst or other hydrogenation catalysts might also beused in the hydrogenation zone of myapparatus.

The reactor should also include provisions for the introduction of acarrier gas to be mixed with the nitrogen-containing sample materialprior to the hydrogenation zone, which successively sweeps the samplethrough the reactor and into the analyzing means. The optimum carriergas for use in my invention is hydrogen because it is needed in thehydrocracking and hydrogenation zones of the reactor and is also usedfor the determination of nitrogen when using the preferred coulometrictitrating apparatus. Preferably, the hydrogen carrier gas should behumidified and heated to about 200 F. before being introduced into thereactor in order to inhibit coking of the hydrocracking catalyst.

As stated previously, carrier gas leakage becomes a problem whenintroducing heavy, viscous nitrogen-containing samples into theapparatus. 1 have solved this probiem by providing the reactor with anovel inlet means. This inlet means includes a vapor tight chambercapable of communication alternatively with the reactor vaporizing zoneand the exterior of the apparatus. An embodiment of such an inlet meanscomprises a substantially vertical conduit in communication with thereactor vaporizing zone. The conduit contains a plug mounted forrotation within the conduit flow passage so as to prevent the passage ofmaterial through the conduit. A well or other type of receptacle ispresent within the plug and adapted to receive a sample containerintroduced into the conduit. Due to the substantially vertical nature ofthe conduit, the sample container is held within the well bygravitational forces. Rotation of the plug within the conduit reorientsthe well from its container-receiving position to a position such thatthe well communicates with the reactor vaporizing zone. Again, becauseof the substantially vertical nature of the conduit, any samplecontainer present within the well drops from the well and is introducedinto the reactor vaporizing zone. It is evident the plug must beproperly seaied within the conduit flow passage to prevent the escape ofcarrier gas from the reactor.

Another embodiment of the above-described inlet means comprises asubstantially vertical tube having a'lower end in communication with thevaporizing zone of the reactor and an upper end adapted for receivingsamples from a source outside of the reactor. The tube has mountedwithin it a large bore stopcock. A stopcock made of Teflon would be mostsuitable, although one made from Pyrex glass would also be satisfactory.The stopcock has its bore sealed at one end by the presence of a septum,preferably composed of silicone rubber. This septum prevents materialfrom passing through the stopcock bore, but is also of such a naturethat it can be pierced by a hypodermic needle and still remainsubstantially vapor tight once the needle is removed. Thus a samplecontainer receptacle is formed by the walls of the stopcock bore and theseptum. In using this novel inlet means, the stopcock is first turned sothat the unsealed end of the bore is in communication with the upper endof the tube. A container holding the sample material, sized so as to fitcompletely within the container receptacle, is inserted into the tube sothat it drops into the container receptacle. In order to introduce thesample container into the reactor, the stopcock is merely turned about180. This permits the sample container to fall from the receptacle intothe reactor vaporizing zone. It is essential that the sample containerbe composed of a material which melts at the temperature encounteredwithin the vaporizing zone so that the sample can be vaporized, mixedwith the carrier gas and passed through the reactor.

Any apparatus for ammonia determination may be used as the analyzingmeans of my invention. This includes, but is not limited to,colorimetric and acidimetric analyzers. However, a particularlydesirable type of analyzing means which is conveniently adapted for usewith my invention is the automatic coulometric titration apparatusdescribed in U.S. Pat. No. 3,461,042. The automatic coulometrictitration apparatus is particularly convenient for use with myinvention, not only because of its sensitivity and rapidity of analysis,but also because the hydrogen gas required is readily available as thecarrier sweep gas. Since the automatic coulometric titration apparatusand method are fully described in the above-mentioned patentapplications, there is no need to repeat such a description here.

The method and apparatus of this invention may be more fully understoodby referring to FIGS. 1 and 2. It is understood that in FIG. 1, allconnecting lines are of% inch copper tubing unless other wise noted. Asource of hydrogen gas is connected to water tank 11 of humidifier 12via line 13 and valve 14. Bypass line 15, using valve 150 as a bypasscontrol, is connected to line 13 ahead of valve 14 to permit the flow ofdry hydrogen gas around water tank 11. Water tank 11 is wrapped withheating tape (not shown) to permit the heating of the water containedtherein to a temperature of at least 200 F. Line 16 extends from theoutlet of water tank 11 and connects to Swagelock joint 18. Bypass line15 connects to outlet line 16 ahead ofhydrogen flow valve 17.

Reactor 19 consists of a is-inch O.D. quartz U-shaped tube having asample inlet 20 attached to vertical arm 19a. Sample inlet 20 is ofPyrex glass and contains a large 8 mm. bore Pyrex stopcock 21. Sampleinlet 20 is attached to reactor 19 by graded seal 22. Graded seal 22 isrequired in order to bond Pyrex sample inlet 20 to quartz vertical arm19a. Reactor 19 is provided with hydrogen inlet 23 at a point somewhatbelow graded seal 22. Hydrogen inlet 23 connects with Swagelock joint 18by butyl rubber tubing joint 24 and line 25. Tubing joint 24 is neededto provide sufficient flexibility to minimize breakage of hydrogen inlet23 when connecting or disconnecting humidifier 12 from the reactor.Within reactor 19 are vaporizing zone 16, hydrocracking zone 27 andhydrogenation zone 28. Vaporizing zone 26 is in the horizontal portionof reactor 19 and is provided with a resistance wire heating means 29.Heating means 29 should be capable of providing temperatures of at least1,030 F. within vaporizing zone 26.

Hydrocracking zone 27 and hydrogenation zone 28 are both located invertical arm 31 of reactor 19. Hydrocracking catalyst 30 is presentwithin hydrocracking zone 27 and comprises 0.6 percent rhodium on asilica-alumina cracking catalyst support. This catalyst is prepared bydissolving the calculated amount of rhodium chloride in the maximumamount of water (predetermined by titration) that the silicaaluminasupport can absorb without appearing "wet." The rhodium chloridesolution and silica-alumina support are mixed, air-dried, and pelletedto 56-inch pellets. These pellets are calcined at l,020 F. for 2 hoursand then ground to 16-35 mesh. Above hydrocracking catalyst 30 is a bedof reagent grade nickel granules 32, also having a size of from 16 to 35mesh. Hydrocracking zone 27 is provided with a heating means, such as afurnace (not shown) which keeps the hydrocracking catalyst 30 and nickelgranules 32 at about l,400 F. This furnace should be capable ofmaintaining hydrocracking catalyst 30 and nickel granules 32 at atemperature of about l,650 F.

A hydrogenation catalyst 33, comprising nickel on a magnesia base, islocated in hydrogenation zone 28, which is above hydrocracking zone 27.Hydrogenation zone 28 is provided with a heating means, such as afurnace (not shown), which ordinarily keeps hydrogenation catalyst 33 ata temperature of about 680 F. This furnace should be capable of heatinghydrogenation catalyst 33 to about l,100 F.

Outlet 34 of reactor 19 connects to inlet 35 of titration cell 36 viaglass connection line 37. Titration cell 36 electrically connects tocoulometer 38, which in turn electrically connects to recorder 39.Titration cell 36 contains a suitable electrolyte such as aqueous sodiumsulfate at a pH of about 5.95. Such an electrolyte may be prepared bydissolving about 5 g. of reagent grade sodium sulfate in 1 liter ofion-exchanged water.

In using the apparatus, it is necessary to first obtain properly sizedsamples. I have found that best results are obtained when sample sizesare selected according to the following table:

Sample size, mg. Nitrogen Content, I:

0. l0.4 3-6 0.4-1 0.3-3 2-10 (ml-0.2

if the nitrogen-containing sample material is volatile such as naphthaor refinery waste water, a measured amount can be introduced intoreactor 19 by means of a long needle syringe inserted through thesilicone rubber septum 21a of stopcock 21. Any samples, but particularlyviscous ones which cannot be forced through a syringe, can beencapsulated in tin sample container 40. Sample container 40 is about5X13 mm. in size.

The apparatus and method of my invention have been used to analyze anumber of different nitrogen-containing samples and the results obtainedhave been compared with other methods of analyses. Table 1 shows resultsof analyses performed with lubricating oils or base stock lubricatingoils. The nitrogen content in the samples ranged from about 50 p.p.m. toover 1,000 ppm. The data presented in table 2 are the results of similaranalyses on oil additives and miscellaneous oils. These samples hadnitrogen contents much higher than those shown in table 1.

TABTEII Nitrogen,

Run

Sample Kjeldahl Coulometric DiltZ, Z:

Blend lube oil 0.108 0106 2.0

(Dumas) J Oil additive 6.22 6.00 3,7

(Dumas) K Oil additive 1.53 L55 [.3 L

Oil additive [.43 1.46 2.1 M

Additive package 0.56 0.55 2.0 N

Additive package 0.5 B 0.56 2.0

Aluminum rolling oil 025 0.27 3.7 P

Hydraulic fluid 0.0802 0.0800 02 Except as indicated, all comparisonruns were made using the Kjeldahl method. Two comparison runs were madeusing the Dumas method because the compounds being tested containednitrogen-nitrogen linkages and therefore could not be analyzed by theKjeldahl method. All samples analyzed in tables l and ll were similar inviscosity and boiling points.

In order to test the apparatus on nitrogen-containing samples having awide range of boiling points, analyses were performed on a series oflight cycle oils, heavy cycle oils and decanted oils. Again, theKjeldahl method was used for the purposes of comparison. Results fromthese analyses are presented in table lil.- Run U was used to calibratethe coulometric titration apparatus. Theoretically, calibration is notrequired since the amount of titrant generated can be calculated fromthe coulombs used in the titration. However, calibration simplifies theuse of the equipment. The samples analyzed cover a boiling point rangefrom about 250 F. to about 1,200 F. Even for the higher boiling samples,it was possible to keep the nickel-magnesia hydrogenation catalyst atabout a 700 F. temperature. If hydrocracking did not take place prior tohydrogenation, the samples having boiling points in the l,000 F. rangewould not have been correctly analyzed.

TABLE III Analyses of LCO, l-lCO and DO The apparatus described abovegives quick and accurate determinations of nitrogen content. Nitrogenvalues can be reported within fifteen minutes after the sample isaccepted for analysis. Thus, my invention can be used both to monitorplant processes or to make quick checks of certain blending operations.The catalysts used in my invention have long life times. Over 400analyses were carried out on a single catalyst filling. The procedure issimple, and once the equipment is set up and operating conditions havestabilized, relatively unskilled personnel can perform the actualdeterminations.

The foregoing description of the present invention is given forillustrative purposes only and various modifications in the apparatusand in the process itself will become apparent to the skilled workerfrom a reading of the description. However, such modifications areintended to fall within the scope of my invention.

Having described the invention, what I claim is:

1. In a method for automatically determining the nitrogen content of anorganic material, by the steps of converting the nitrogen to ammonia bymeans of passing the organic material through a hydrogenation zonecontaining a nickel-on-magnesia catalyst and then determining thequantity of ammonia present, the improvement comprising firstintroducing the organic material into a vaporizing zone, mixing thevaporized organic material with hydrogen, passing the vaporized materialand hydrogen through a hydrocracking zone containing a hydrocrackingcatalyst at a temperature sufficient to hydrocrack the organic material,and then passing the vaporized hydrocracked product to saidhydrogenation zone.

2. The method of claim 1' wherein said hydrocracking catalyst comprisesrhodium on a molecular sieve base.

3. The method of claim 2 wherein said hydrocracking catalyst comprisesabout 0.6 percent rhodium.

4. The method of claim I wherein said hydrocracking catalyst comprisesrhodium on a silica-alumina base.

5. The method of claim 4 wherein said hydrocracking catalyst includesabout 0.6 percent rhodium.

6. The method of claim 1 wherein said organic material is mixed withhydrogen gas prior to being passed through said hydrocracking zone.

7. The method of claim 6 wherein said hydrogen is humidified to inhibitcoking of the hydrocracking catalyst.

8. A method for automatically determining the nitrogen content of anorganic material comprising:

a. Passing said organic material through a vaporizing zone in thepresence of humidified hydrogen, wherein said organic material isconverted to a vapor phase;

b. Passing the effluent from said vaporizing zone which includesvaporizing organic material and humidified hydrogen through ahydrocracking zone, said hydrocracking zone including a hydrocrackingcatalyst,

at a temperature in the range of between about l,400 F.

and about l,440 F.;

c. Passing the effluent from said hydrocracking zone through a bed ofnickel granules at a temperature in the range of between about l,400 F.and about l,440 F.;

d. Contacting the effluent from said bed of nickel granules with anickel-on-magnesia catalyst at a temperature in the range of betweenabout 680 F. and about 7 l 5 F., to convert the nitrogen in said organicmaterial to ammonia; and

e. Coulometrically titrating the ammonia produced in step (d), theamount of titrant required for said titration being a measure of thenitrogen content in said organic materi al.

9. The method of claim 8 wherein said hydrocracking catalyst comprises0.6 percent rhodium on a molecular sieve base.

10. The method of claim 8 wherein said hydrocracking catalyst comprises0.6 percent rhodium on a silica-alumina base.

11. An apparatus for determining the nitrogen content of an organicmaterial comprising:

a. A reactor including in series:

i. a vaporizing zone including a heating means for vaporizing saidorganic material;

ii. a hydrocracking zone including a hydrocracking catalyst bed andmeans for maintaining said hydrocracking catalyst bed at a temperaturebetween about 1,400 F. and 1,440 F; and

iii. a hydrogenation zone containing a nickel-on-magnesia hydrogenationcatalyst bed and means for maintaining said hydrogenation catalyst bedat a temperature between about 680 F. and 715 F., and

b. Analyzing means for quantitatively detecting the presence of ammonia,said analyzing means in fluid communication with said reactor whereinsaid organic material passes sequentially:

c. Through said vaporizing zone to insure that said organic material isin the vapor state;

d. Through said hydrocracking zone to convert said organic material tolower molecular weight components;

e. Through aid hydrogenation zone to convert any nitrogen present toammonia; and

wherein effluent from said hydrogenation zone is passed to saidanalyzing means to determine the amount of ammonia present therein.

12. The apparatus of claim 11 wherein said supply means further includesmeans for humidifying said hydrogen.

13. The apparatus of claim l 2 wherein said supply means furtherincludes a temperature control means whereby said humidified hydrogenmay be supplied to the reactor at a temperature of about 200 F.

14. The apparatus of claim 11 wherein said analyzing means is acoulometric titrator, wherein said hydrocracking catalyst comprises 0.6percent rhodium on a molecular sieve base, and wherein saidhydrocracking zone further includes at least one bed comprising nickelgranules.

15. The apparatus of claim 14 wherein said analyzing means is acoulometric titrator, wherein said hydrocracking catalyst comprises 0.6percent rhodium on silica-alumina, and wherein said hydrocracking zonefurther includes at least one bed comprising nickel granules.

16. The apparatus of claim 11 further including a hydrogen supply meansin fluid communication with said reactor and adapted to supply hydrogento said reactor at a point within said reactor prior to saidhydrocracking zone.

17. A method for automatically determining the nitrogen content of anorganic material comprising:

a. introducing said organic material into a vaporizing zone in thepresence of humidified hydrogen by the steps of 1. encapsulating saidorganic material in a substance which melts at a temperature less thanthe temperature within the vaporizing zone; and

2. introducing the encapsulated organic material into the va orizingzone;

. passing effluent from said vaporizing zone which includes vaporizedorganic material and humidified hydrogen through a hydrocracking zone,said hydrocracking zone including a hydrocracking catalyst, at atemperature in the range of between about l,400 F. and about l,440 F.;

. passing effluent from said hydrocracking zone through a bed of nickelgranules at a temperature in the range of between about l,400 F. andabout M402 F.;

d. contacting effluent from said bed of nickel granules with anickel-on-magnesia catalyst at a temperature in the range of betweenabout 680 F. and about 715 F.. to convert the nitrogen in said organicmaterial to ammonia; and

e. coulometrically titrating the ammonia produced in step (d), theamount of titrant required for said titration being a measure of thenitrogen content in said organic material.

18. The method of claim 17 wherein the encapsulating material is tin.

19. An apparatus for determining the nitrogen content of an organicmaterial comprising:

a. a reactor including in series:

I. a vaporizing zone including a heating means for vaporizing saidorganic material;

2. a hydrocracking zone including a hydrocracking catalyst bed and meansfor maintaining said hydrocracking catalyst bed at a temperature betweenabout l,400 F. and L440 F; and 3. a hydrogenation zone containing anickel-on-magnesia hydrogenation catalyst bed and means for maintainingsaid hydrogenation catalyst bed at a temperature between about 680 F.and 715F.; and

b. inlet means to said reactor comprising:

1. a substantially vertical conduit having an upper end, a lower endwhich is in communication with said vaporizing zone, and an interiorpassageway along its longitudinal axis; and

2. a plug having a well, said plug being rotatably mounted within saidpassageway, said well being in registration with the passage of saidconduit so that as said plug is rotated within said bore, the wellalternatively communicates with the upper end of said conduit and thelower end of said conduit;

c. analyzing means for quantitatively detecting the presence of ammonia,said analyzing means in fluid communication with said reactor whereinsaid organic material passes sequentially:

d. through said vaporizing zone to insure that said organic material isin the vapor state;

e. through said hydrocracking zone to convert said organic material tolower molecular weight components;

fr through said hydrogenation zone to convert any nitrogen present toammonia; and

wherein effluent from said hydrogenation zone is passed to saidanalyzing means to determine the amount of ammonia present therein.

20. An apparatus for determining the nitrogen content of an organicmaterial comprising;

a. a reactor including in series:

1. a vaporizing zone including a heating means for vaporizing saidorganic material;

2. a hydrocracking zone including a hydrocracking catalyst bed and meansfor maintaining said hydrocracking catalyst bed at a temperature betweenabout l,400 F. and 1440 F.;

3. a hydrogenation zone containing a nickel-on-magnesia hydrogenationcatalyst bed and means for maintaining said hydrogenation catalyst bedat a temperature between about 680 F. and 7 l 5 F.;

b. inlet means to said reactor comprising:

1. a substantially vertical tube having an upper end and a lower endwhich is in communication with said vaporizing zone, and a passagewayalong its longitudinal axis, and a hole passing through the surface ofsaid tube communicating with the passageway of said tube; and

2. a stopcock mounted for rotation within said hole in said tube, saidstopcock at all times preventing flow through the passageway in saidtube, said stopcock having a flow passage, one end of which is sealed;

c. analyzing means for quantitatively detecting the presence of ammonia,said analyzing means in fluid communication with said reactor whereinsaid organic material passes sequentially;

d. through said vaporizing zone to insure that said organic material isin the vapor state;

e. through said hydrocracking zone to convert said organic material tolower molecular weight components;

f. through said hydrogenation zone to convert any nitrogen present toammonia; and wherein effluent from said hydrogenation zone is passed tosaid analyzing means to determine the amount of ammonia present therein.

i t t i t

2. The method of claim 1 wherein said hydrocracking catalyst comprisesrhodium on a molecular sieve base.
 2. introducing the encapsulatedorganic material into the vaporizing zone; b. passing effluent from saidvaporizing zone which includes vaporized organic material and humidifiedhydrogen through a hydrocracking zone, said hydrocracking zone includinga hydrocracking catalyst, at a temperature in the range of between about1,400* F. and about 1,440* F.; c. passing effluent from saidhydrocracking zone through a bed of nickel granules at a temperature inthe range of between about 1,400* F. and about 14402 F.; d. contactingeffluent from said bed of nickel granules with a nickel-on-magnesiacatalyst at a temperature in the range of between about 680* F. andabout 715* F., to convert the nitrogen in said organic material toammonia; and e. coulometrically titrating the ammonia produced in step(d), the amount of titrant required for said titration being a measureof the nitrogen content in said organic material.
 2. a hydrocrackingzone including a hydrocracking catalyst bed and means for maintainingsaid hydrocracking catalyst bed at a temperature between about 1,400F.and 1,440* F; and
 2. a plug having a well, said plug being rotatablymounted within said passageway, said well being in registration with thepassage of said conduit so that as said plug is rotated within saidbore, the well alternatively communicates with the upper end of saidconduit and the lower end of said conduit; c. analyzing means forquantitatively detecting the presence of ammonia, said analyzing meansin fluid communication with said reactor wherein said organic materialpasses sequentially: d. through said vaporizing zone to insure that saidorganic material is in the vapor state; e. through said hydrocrackingzone to convert said organic material to lower molecular weightcomponents; f. through said hydrogenation zone to convert any nitrogenpresent to ammonia; and wherein effluent from said hydrogenation zone ispassed to said analyzing means to determine the amount of ammoniapresent therein.
 2. a hydrocracking zone including a hydrocrackingcatalyst bed and means for maintaining said hydrocracking catalyst bedat a temperature between about 1,400* F. and 1440* F.;
 2. a stopcockmounted for rotation within said hole in said tube, said stopcock at alltimes preventing flow through the passageway in said tube, said stopcockhaving a flow passage, one end of which is sealed; c. analyzing meansfor quantitatively detecting the presence of ammonia, said analyzingmeans in fluid communication with said reactor wherein said organicmaterial passes sequentially; d. through said vaporizing zone to insurethat said organic material is in the vapor state; e. through saidhydrocracking zone to convert said organic material to lower molecularweight components; f. through said hydrogenation zone to convert anynitrogen present to ammonia; and wherein effluent from saidhydrogenation zone is passed to said analyzing means to determine theamount of ammonia present therein.
 3. a hydrogenation zone containing anickel-on-magnesia hydrogenation catalyst bed and means for maintainingsaid hydrogenation catalyst bed at a temperature between about 680* F.and 715* F.; b. inlet means to said reactor comprising:
 3. ahydrogenation zone containing a nickel-on-magnesia hydrogenationcatalyst bed and means for maintaining said hydrogenation catalyst bedat a temperature between about 680* F. and 715* F.; and b. inlet meansto said reactor comprising:
 3. The method of claim 2 wherein saidhydrocracking catalyst comprises about 0.6 percent rhodium.
 4. Themethod of claim 1 wherein said hydrocracking catalyst comprises rhodiumon a silica-alumina base.
 5. The method of claim 4 wherein saidhydrocracking catalyst includes about 0.6 percent rhodium.
 6. The methodof claim 1 wherein said organic material is mixed with hydrogen gasprior to being passed through said hydrocracking zone.
 7. The method ofclaim 6 wherein said hydrogen is humidified to inhibit coking of thehydrocracking catalyst.
 8. A method for automatically determining thenitrogen content of an organic material comprising: a. Passing saidorganic material through a vaporizing zone in the presence of humidifiedhydrogen, wherein said organic material is converted to a vapor phase;b. Passing the effluent from said vaporizing zone which includesvaporizing organic material and humidified hydrogen through ahydrocracking zone, said hydrocracking zone including a hydrocrackingcatalyst, at a temperature in the range of between about 1,400* F. andabout 1,440* F.; c. Passing the effluent from said hydrocracking zonethrough a bed of nickel granules at a temperature in the range ofbetween about 1,400* F. and about 1,440* F.; d. Contacting the effluentfrom said bed of nickel granules with a nickel-on-magnesia catalyst at atemperature in the range of between about 680* F. and about 715* F., toconvert the nitrogen in said organic material to ammonia; and e.Coulometrically titrating the ammonia produced in step (d), the amountof titrant required for said titration being a measure of the nitrogencontent in said organic material.
 9. The method of claim 8 wherein saidhydrocracking catalyst comprises 0.6 percent rhodium on a molecularsieve base.
 10. The method of claim 8 wherein said hydrocrackingcatalyst comprises 0.6 percent rhodium on a silica-alumina base.
 11. Anapparatus for determining the nitrogen content of an organic materialcomprising: a. A reactor including in series: i. a vaporizing zoneincluding a heating means for vaporizing said organic material; ii. ahydrocracking zone including a hydrocracking catalyst bed and means formaintaining said hydrocracking catalyst bed at a temperature betweenabout 1,400* F. and 1,440* F; and iii. a hydrogenation zone containing anickel-on-magnesia hydrogenation catalyst bed and means for maintainingsaid hydrogenation catalyst bed at a temperature between about 680* F.and 715* F.; and b. Analyzing means for quantitatively detecting thepresence of ammonia, said analyzing means in fluid communication withsaid reactor wherein said organic material passes sequentially: c.Through said vaporizing zone to insure that said organic material is inthe vapor state; d. Through said hydrocracking zone to convert saidorganic material to lower molecular weight components; e. Through saidhydrogenation zone to convert any nitrogen present to ammonia; andwherein effluent from said hydrogenation zone is passed to saidanalyzing means to determine the amount of ammonia present therein. 12.The apparatus of claim 11 wherein said supply means further includesmeans for humidifying said hydrogen.
 13. The apparatus of claim 12wherein said supply means further includes a temperature control meanswhereby said humidified hydrogen may be supplied to the reactor at atemperature of about 200* F.
 14. The apparatus of claim 11 wherein saidanalyzing means is a coulometric titrator, wherein said hydrocrackingcatalyst comprises 0.6 percent rhodium on a molecular sieve base, andwherein said hydrocracking zone further includes at least one bedcomprising nickel granules.
 15. The apparatus of claim 14 wherein saidanalyzing means is a coulometric titrator, wherein said hydrocrackingcatalyst comprises 0.6 percent rhodium on silica-alumina, and whereinsaid hydrocracking zone further includes at least one bed comprisingnickel granules.
 16. The apparatus of claim 11 further including ahydrogen supply means in fluid communication with said reactor andadapted to supply hydrogen to said reactor at a point within saidreactor prior to said hydrocracking zone.
 17. A method for automaticallydetermining the nitrogen content of an organic material comprising: a.introducing said organic material into a vaporizing zone in the presenceof humidified hydrogen by the steps of
 18. The method of claim 17wherein the encapsulating material is tin.
 19. An apparatus fordetermining the nitrogen content of an organic material comprising: a. areactor including in series:
 20. An apparatus for determining thenitrogen content of an organic material comprising; a. a reactorincluding in series: